Transmission



G. E. FLINN,,

TRANSMISSION Dec. 9, 1952 Filed June 18 1945 10 Sh eets-Sheet l Int/6721 07".-

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TRANSMISSION l0 Sheets-Sheet 2 Dec. 9, 1952 Filed June 18 1945 III Zinn

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TRANSMISSION Filed June 18 1945 10 Sheets-Sheet 3 NAN/FOL D HAN/FOLD lllP-ih- Dec. 9, 1952 G. E. FLINN 2,620,667

' TRANSMISSION Filed June 1a, 1945 10 Sheets-Sheet 4 l0 HRH.

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TRANSMISSION Filed June 18 1945 10 Sheets-Sheet 5 HAN/FOL 0 MAN/FOLD fizz/eni or' I George E Zzjnn G. E. FLINN TRANSMISSION Dec. 9, 1952 10 Sheets-Sheet 6 Filed June 18 1945 .fnvenforfi' Georzge Z: Z21

Dec. 9,1952 5 FLlNN 2,620,667

TRANSMISSIQN Filed June 18, 1945 10 Sheets-Sheet 7 MAN/FOL D fizz an ar Geqqge E (inn G. E. FLlNN TRANSMISSION Dec. 9, 1952 10 Sheets-Sheet 8 Filed June 18, 1945 mNN fill/6771. 0 7*" 6 ?0719'6 E F inn G. E. FLINN TRANSMISSION Dec. 9, 1952 10 Sheets-Sheet 9 Filed June 18, 1945 fizverzi or" 6630719: E f inn Dec. 9, 1952 E, UN 2,620,667

TRANSMISSION Filed June 18, 1945 10 Sheets-Sheet 10 MAN/FOL D MA N/FOL D I j7ll /e7ll 0f'" 612071965 inn lllli-h I M Patented Dec. 9, 1952 TRANSMISSION George E. Flinn, Muncie, Ind., assignor to Borg- Warner Corporation, Chicago, 111., a corporation of Illinois Application June 18, 1945, Serial No. 599,993

35 Claims. 1

My invention relates to transmissions for automotive vehicles and more particularly to control mechanisms for such transmissions. Still more particularly my invention relates to such transmission control mechanisms which are under the control of the accelerator of the vehicle.

It is an object of my invention to provide a transmission having three forward speed ratios and an accelerator controlled transmission control mechanism by means of which the transmission may be shifted progressively from first to second to third speed ratios but not directly from first to third speed ratios.

It is a further object of the invention to provide an improved transmission control mechanism wherein a clutch between the engine of the vehicle and the transmission is disengaged and the throttle of the engine is put into engine idling condition automatically when a shift is made, and more particularly it is an object to provide such a mechanism wherein the shift is completed after once being initiated by means of the accelerator regardless of the subsequent movement of the accelerator after the shift has been initiated. To this end it is an object to provide a motor for making the shift of the transmission and which operates on an electric switch when the motor is operative, with the electric switch being connected with the eng ne idling means and the clutch disengaging means for rendering them operative. It is contemplated that the motor for making the shift shall preferably be of the vacuum type and shall be such as to make a portion of the shift while ball and detent means are provided for making the remainder of a shift movement. The switch connected with the vacuum motor shall then be in changed electrical condition only while the vacuum motor is eifective to make its portion of the shift and prior to a completion of the shift by the ball and detent means. In connection with forcing the shift, it is an object to provide electric relays in connection with the accelerator which are so arranged that when once energized-by movement of the accelerator, the' relays remain energized even though the accelerator is moved prior to a completing of the shift.

It is another object of my invention to provide a. governor in the transmission controlling mechanism whereby the transmission can only be upshifted from first to second speed ratio above a predetermined speed of the driven shaft of the transmission and of the vehicle and from second to third speed ratio only above a predetermined higher speed of the driven shaft and vehicle. It is a further object to provide a governor connection in the control mechanism whereby the transmission cannot be downshifted below a predetermined speed of the driven shaft and of the vehicle whereby to avoid excessive speeds of the engine.

It is also the object of my invention to provide a clutch engaging mechanism under the control of the accelerator which operates to engage the clutch when the accelerator is moved toward open throttle position, and it is an object to provide such a mechanism connecting the accelerator and clutch whereby the accelerator may not be utilized for disengaging the clutch below a predetermined speed of the driven shaftand of the vehicle.

It is another object of the invention to provide a coast switch in a transmission controlling mechanism which functions to put the transmission in a reduced gear speed ratio and prevents the shifting out of the reduced speed ratio regardless of how the accelerator is operated whereby the engine of the vehicle may be used as a brake in descending steep grades.

In certain embodiments of the invention comprising a vacuum motor of the piston type having spring means therein for returning the piston of the motor to neutral position, the motor being connected to shift the transmission, it has been found that the spring means acts more quickly than the vacuum can be utilized for moving the piston whereby the switch connected with the piston for disengaging the clutch and closing the engine throttle is not held in the same changed electrical condition to maintain the clutch disengaged and the throttle closed for the complete shift movement of the piston. It is thus another object of the invention to provide another switch actuated by the motor which is effective when the mechanism is conditioned for shifting from either second speed ratio to third speed ratio or vice versa for maintaining the clutch disengaged and the throttle closed throughout the complete movement of the vacuum piston regardless of this action of the spring means.

The invention disclosed and claimed in this application is similar in some respectsto the inventions disclosed and claimed in the application of John M. Simpson, George E. Flinn, and Carl W. Osborne, Serial No. 599,992, filed June 18, 1945, and the application of Palmer'Orr and 3 George E. Flinn, Serial No. 599,994, filed June 18, 1945.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of certain preferred embodiments illustrated in the accompanying drawings, wherein:

Fig. l is a longitudinal sectional view of an automatic transmission connected with a vehicle engine;

Fig. 2 is a diagrammatic illustration of the control mechanism for the transmission shown in Fig. l, the ignition switch for the vehicle being open and the accelerator being in closed throttle position;

Fig. 3 is a view similar to Fig. 2 but with the ignition switch being closed and with the vehicle engine being in ope-ration to supply a vacuum;

Fig. 5 is a view similar to Fig. 4 but with the I vehicle traveling above five miles per hour and with the accelerato' released to initiate a shift of the transmission from low to second speed ratios;

Fig. 6 is a view similar to Fig. 5 but after a shift from first speed ratio to second speed ratio has taken place, with the accelerator still released;

Fig. 7 is view similar to Fig. 6 but with the accelerator depressed after the shift from first to'second speed ratios has taken place;

Fig. 8 is a view similar to Fig. 7 but with the vehicle travelling above ten miles per hour and with the accelerator released to cause a shift from second speed ratio to high speed ratio;

Fig. 9 is a view similar to Fig. 8 but with the shift to high speed ratio completed and with the accelerator depressed to cause a downshift from third speed ratio to second speed ratio;

.Fig. 10 is .a diagrammatic illustration of a modified control mechanism for the transmission shown in Fig. l, with the mechanismbeing shown with the vehicle speed being above ten miles per hour and with the accelerator being in open throttle or kickdown position; and

Fig. '11 is a diagrammatic illustration of one of the relays used in the transmission control mechanisms illustrated in Figs. 2 to 10.

Like characters of reference designate like parts in the several views.

Referring now in particular to Fig. 1 of the drawings, the illustrated transmission is one particularly suitable for use in an automotive vehicle and comprises a drive shaft i0 and a driven shaft 11. The drive shaft 1'0 is adapted to be driven by means of the engine 12 of the vehicle which is the ordinary intern-a1 combustion engine usually used in such vehicles. The shaft H) is connected with the engine by means of a friction clutch l3 and a hydraulic coupling It. The hydraulic coupling It may be-of any suitable wellknown construction and comprises an impeller element 15 and arotor element 16. The element 15 is driven by the motor I2 and fluid in the device [4 functions on such driving of the impeller element to drive the rotor element l5 of the device.

The clutch 13 comprises a driving element 11 and a driven element 18. The driving element is connected with the rotor 16 of the coupling device ['4 and the driven clutch element I8 is connected with the drive shaft 10 of the transmission. The driven clutch element !8 is clamped between a pressure plate 19 and the driving element ll of the clutch. Radially extending clutch levers 29 act on the pressure plate 29 by means of struts 2i, and these levers are pivotally mounted on studs 22 which are fixed with respect to a clutch cover 23 which rotates with the driving element 17. Springs 24 are disposed between the cover 23 and the pressure plate 19 for yieldingly holding the pressure plate against the driven element 18 for maintaining the clutch engaged. A collar 25 is slidably disposed on a housing portion 23 for the transmission, and this collar is disposed to act against the clutch levers 2c to move the pressure plate 19 rearwardly by means of the struts 2! to disengage the clutch. The collar 25 is acted on by means of a release lever 27 fixed on a shaft 28.

The drive shaft ii is journaled in the housing for the transmission by means of a roller bearing 36, and the driven shaft I l is journaled in the housing 35 by means of the roller bearing 31. The shaft H is piloted in the shaft [0 by means of rollers -38, as shown. The drive shaft I0 is formed with a spur gear 39, and this gear is in mesh with a gear of a gear cluster 41. A countershaft 42 is provided in the housing 35, and the gear cluster 4! is rotatably disposed on the countershaft. A gear 43 is rotatably disposed on the driven shaft l I and is in mesh with a gear 43-4 on the gear cluster 4i. Another gear 45 is disposed on the driven shaft H and is supported with respect to the shaft by means of a hub 46 splined on the shaft and a one-way roller clutch ii. The roller clutch may be of the ordinary type comprising rollers disposed between opposite cam surfaces, and the clutch is such that it will engage when the gear 45 is driven in the forward direction for thereby driving the shaft H. The gear cluster 4! also comprises gears 48 and 49 which are adapted to cooperate with the gear 45. The gear 49 is in mesh with an idler gear 50 which is rotatably supported by any suitable means with respect to the housing 35. The gear 45 depending on the position to which it is moved on the shaft ll may mesh either with the gear 43 or with the idler gear as. An element 5! having external teeth 52 is splined on the shaft H, and the gear 45 is provided with internal teeth 53. The teeth 53 are adapted to mesh with the teeth 52 when the gear 55 is moved rearwardly of the transmission to mesh with the idler gear 50 whereby the one-way clutch 47 is rendered inefiective.

A double positive type clutch 54 is provided for connecting either the shaft I0 or the gear 43 with the shaft .II. This clutch comprises an internally toothed collar 55 slidably and nonrotatably disposed on a hub 56 which is splined to shaft H. The shaft i0 is provided with teeth 51 and the gear 43 is provided with teeth 58 which are adapted to be meshed with the internal teeth of the collar 55 depending on the direction in which the collar is moved. A synchronizer ring 59 of any suitable well-known construction is disposed on each side of the collar 55 on the shaft Ii] and on the gear 33 for synchronizing the speed of the collar with either the teeth 51 or the teeth 58 before engagement of the collar with the teeth. A yoke 69 is provided which fits in a groove formed in the collar 55 for shifting the collar as will be hereinafter described. The transmission is also controlled by means of a governor which will be hereinafter described, and the governor is driven from the driven shaft II by means of gearing 6|.

The illustrated transmission provides three speed ratios in forward drive and one speed ratio in reverse drive. When the gear 45 is shifted into mesh with the gear 48, the transmission is conditioned for low speed forward drive and the drive is from the shaft I9 through the gears 39 and 49, the gear cluster 4|, the gears 48 and 45,

the one-way clutch 41 and the hub 46 to the shaft II. The shaft I9 is driven from the engine I2v through the coupling I4 and clutch I3 as will be understood. Second speed forward drive is provided by shifting the collar 55 to mesh with the teeth 58. The drive is then from the shaft I9 through the gears 39 and 49, the gear cluster 4|, the gears 44 and 43, the teeth 58, the collar 55 and the hub 56 to the shaft II. High or third speed forward is provided by shifting the collar 55 to mesh with the teeth 51. The drive is then from the shaft I9 through the teeth 51, collar 55 and hub 56 to the shaft II. The gear 45 may be allowed to remain in mesh with the gear 48 for both second and high speeds forward, and the clutch 41 overruns. For reverse drive the gear 45 is shifted into mesh with the idler gear 50, with the collar 55 being in itsneutral position in which it is shown in Fig. l. The drive is then from the shaft I9 through the gears 39 and 49, the gear cluster 4|, the gears 49, 59 and 45, the teeth 53 and 52, and the element 5| to the shaft I I. The overrunning clutch 41 would overrun for this direction of drive, and the teeth 53 and 52 and the element 5| are thus necessary for reverse drive.

The mechanism for controlling the transmission shown in Fig. 1 comprises in general (see Fig. 2) an ignition switch 65 connected with the battery 66 of the vehicle, a forward conditioning switch 61, a second to high speed ratio conditioning relay 69, a first to second speed ratio conditioning relay 69, a high ratio conditioning relay 19, a coast switch 1|, an electric governor 12, an accelerator switch unit 13 actuated by the accelerator 14 of the vehicle, a throttle for the engine I2 and having a butterfly valve 16 connected by linkage 11 with the accelerator 14 and having another butterfly valve 18 actuated by an electric solenoid 19, an accelerator controlled clutch control or engaging valve 89, a vacuum shut-01f valve 8|, a one-way vacuum valve 82, an electrically controlled vacuum valve 83, a vacuum motor 84 for the clutch I3, a vacuum motor 85 connected. with a lever and a switch assembly 86 for shifting the. collar 55, an electrically operated vacuum valve 81 for the motor 95 and another electrically operated vacuum valve 83 for the motor 85.

The battery 66 on one terminal is grounded in accordance with standard practice, and the battery has its other terminal connected with the ignition switch 65. A fuse or other overload device 95 is connected in series with the switch 65, and the switch 61 is connected in series with the fuse. The relay 68 comprises a relay winding 96, contacts 91, contacts 98 and contacts 99. As will be noted, the winding 96 and the contacts 99 are connected in series with the switch 61.

The relay 69 comprises a relay winding I99, contacts I9I and contacts I92. One of the contacts I92 and one end of the winding I99 are connected with the switch 61, and the other of the contacts I92 is connected with one of the contacts 91, as shown. The other end of the 6 winding I99 is connected with. one of the contacts I9I. W Y

The relay 19 comprises a relay winding. I93, contacts I94 and other contacts I95. ,One 'end of the winding I93 is connected with one of the relay contacts I92 and one of the contacts I is connected with an end of the relay winding 96 as shown. One of the contacts I94 is connected with one end of the winding I93 and the other contact is grounded.

The relays 68, 69 and 19 may be of anyfsuitable construction. The relay'68 is shown in some detail in Fig. 11 and comprises a core 68a on which the winding 96 is disposed. A pivotally mounted armature 68b is disposed at one end of the core and carries a contact 91, a contact 98 and a contact 99. The other contacts 91, 98 and 99 are stationary, and the contacts are made and broken with movement of the armature as is apparent. The relays 69 and 19 are similar in construction to the relay 68 with the contacts ml and I94 and the contacts I92 and I95 corresponding to the contacts 98 and 99, respectively. In the relays 69 and 19 there are no contacts corresponding to the contacts 91.

The, coast switch 1| comprises contacts. I96 and contacts I91 and a switchrarm I98 adapted to-bridge either the contacts I96 or I91. One of the contacts I96 is connected with one of the relay contacts I95. as shown. One of the contacts I91 is connected with the relay-winding I99, and the other is grounded.

The governor 12 may be of any suitable type and is driven fromthe driven shaft |I bythe gearing 6|, and the governor comprises ,contacts I99, .II9, III and H2. ,When the driven shaft II is at rest, the contacts I99 areclosed while the other of the governor contacts are open, as shown in Fig. 2. At approximately a speed of the shaft I I corresponding to five miles per hour speed of the vehicle, the contacts I99 open and the contacts II9 close. At a speed of the shaft corresponding to approximately ten miles per hour, the contacts III close, and the contacts II2 close at approximately forty miles perhour speed of the vehicle. It will be understood that the contacts II9 remain closed at all speeds above five miles per hour, the contacts III remain closed at all speeds above ten miles per hour and the contacts II2 remain closed at all speeds above forty miles per hour. One of each of the sets of contacts I99, II9, III and I I2 is grounded as shown. The other of the contacts H9 is connected with one of the contacts I9I, and the other of the contacts H2 is connected with oneof the contacts 98 as shown.

The accelerator switch 13 comprises contacts II3, contacts II4, contacts 5 and contacts II6, an accelerator plunger I I1, and switch arms II8, I I9 and I29. A spring I2I is provided between the arm I I9 and a. stationary part for yieldingly holding the plunger H1 and accelerator 14 in the closed throttle positions of these parts in whichthey are shown in Fig. 2. A spring I22 is provided for yieldingly holding the switch arm I 29 in its position bridging the contacts II6. One of the contacts H3 is connected with a contact I I6 and also with one of the contacts I I2 of the governor. The other contact I I3 is connected with one of the contacts I99 of the coast switch 1 I. One of the contacts I I4 is connected with one of the contacts I I9 of the governor, and the other of the contacts 4 is connected with one of the contacts I91 of the coast switch. One of the contacts I I5 is connected with the winding I93 chooser speed. One end or the solenoid is' connecteu -"wi-th the 'battei'y't'li through the switch at and "fuse'95'a's shown. n e valve 8'I com rises electric -soiehoiu I 25 for o erating the valve, andtl'iis s'oleiioitl has one end connected to the hatter-y through the fuse and the ignition 's'w-it'ch and its other end is connected with "one or 'the goi'lffio'r 601itacts I 09. The electrically operate vaive ae comprises a solenoid I26, and-o'r-re end or this solenoid also is connected with "the batti y through the fuse and ignition switch; The electrically operated valve -8 I comprises a Solenoid I21 which has one end connected-with "one ofthe contacts 9 1 of the-relay 6 8. 'Thevalve "88 comprises an electric solenoiei zayanaone end "of "this Solenoid is "oonheotd"with b"e of "the contacts 99 or thei'elay 6'8.

The suction motor 85 comprises two noiuing coils I29 and I30.- 'cineenu'oreachhr'thehom- 'in'g coils is grounded as shown' arrdthe end of the coil I29 is connected with "one one oi-"the solenoid I2! and the other en of the con-asp its-connected with one end or the solenoid 'iza, asshow-n.

The lever switch a ss'einhly ce harnesses the I 3'l having' cohtaots I BQ a-IidZ a svi iteh arm :33. two contacts are cofinectedfivith one can or the 'tl'irottleolos'ing so h mes sine also with one can or the selei16i'd' 2e or' t e valve as. The switch was is ggro need es scored with the valve is sever H2 is pivoted at I413 anti-has a spar-rights acting on its end connected with the linlg' l45'. The lever lfl is formed with a screen I5D ted to "cooperate with the lever T40 as w I after describ s; 1 4

When the accelerator T4 is Toeprcsseo; that is, when it is moved in a counterclockwise direction as seen in Fig. 2, the link' IWI is movedto the right seen in this figure'ahu as" indicates by the arrow, and the lever H0 is moved in- -a counterclockwise direction about its connection with the link M3 churn contacts tl fe pdrftion "I50 or the lever IM. -A clearance'ordinarily exists etween the upper end of the lever I40 and the part I50 of the lever I42 before the accelerator has been depressed for purposes which will hereinafter be described. After the lever I 40 has contacted the portion I50, both the levers I40 and I42 thereafter move together'about thepivot M8 in a counterclockwise direction against-the action of the spring M9, and the movement of the lever I42 through the links I45 'and; I45 and 8 th'ebell crank lev'er Ill-moves the butter fiyvalve 16 to open the throttle I5. The butterfly-valve 7 6 is the ordinary throttle opening valve ordihorny foiindin the throttle or an internal combustion "engine, and it is opened by a depressing or the associated accelerator as in ordinary installa'tion's.

The clutch engaging valve is actuated by the accelerator Z4 and the accelerator linkage 11-. The valve comprises a valve block 'I5I hav- -'a passage therein which forms a. part or a vacuum "conduit 152, and the block is provided with a chamber I53 therein which is connected with aconduit I54. -A valve piston I55 is disose-:1 in a cylindrical cavityin the valve block :I 5I, and this cavity is connected by meansof openings I56 with the chamber I53. The piston E55 is provided with lands I57 and I58 fittin in the cavity for the piston, and the piston is hollow as shown. A plunger I59 extends through the valve body I5I, and the plunger is provided "with a stop I58 on an end thereof for limiting its movement. A passage IBI is provided in the valv'e'bod'y, and the plunger I59 is 'provided'with agroove I52 which'coinpletes the passage from the chamber I53 to the atmosphere when the plunger I59 is positioned with its stop I60 against the valve block I5I. The plunger I59 is coniieoted by means of a link I63 with the lever T40, as shown, and the plunger is actuated by "means of the mechanism H as will be described.

7 A plunger I'S l is sli'da bly disposed in a suitable cavity in the valve casing I58, and the plunger is connected with a vacuumdiaphrag'm motor I65 which functions to move the-plunger ac'co'rdin'g'to the amount of vacuum effectiv'eon the diaphragm. The 'motor I65 comprises a spring IE5 effective on the diaphragm and'the motor is connected by means of a conduit 'I'S'I with the chamber I53 in the valve block I5I. The plunger I59, the valve piston I55, andthe plunger I64 are connected together bymeansof a 'flo'ating lever I68. The connection of the lever I63 with thepiston I55 is a simple pivotal con- "nection'whil'e the connections of the lever I68 with the plungers I59 and IE4 are-pin and slot connections as shown.

The conduit I52 is connected toa vacuum con- "duit 1-69 by means of the valves '8I and82 and a conduit "H0. The conduit I59 is connected with -'the manifold'of the engine I2 'or'anyoth'er suitable source of vacuum. The 'valve 82 is "a one-way valve of'any suitable construction which allows "vacuum to be introduced into the con-'- duit I70 but "does not allow atmospheric pressure 'to enter the "conduit I'Ill if the vacuum in the conduit I69 momentarily decreases, 'such as to atmospheric pressure. The valve '81 is a two "position valve comprising a valve t-piston TI'II is actuated by the-solenoid F2 5; Theirv-alve "8 has an atmospheric port '8 hi: in" its casing --through which airinay pass as'win bedescribe'd. the solenoid F2 5 *deener'g'izecl, which ='c'on'dition' itis shown in =Fig'fi 2j the .piston' "IH blocks the conduit '-'I I0 nndrpermit's" atmospheric pressure to enter the "conduit I 52 "through'the p ort 81c. When theisolenoid 125 is energized, the piston "H1 is drawn upwardlyto closej-the port 8Ia to the atmosphere and to' connect the conduits H0 and I52 for therebycausing the vacuum to be'appiied to the valve The chamber I-53-inthe valve-body-I5I (ls-C9D;- nected'to the v-alve"8 3 by means'oi; conduit +54.- The valve 83 is also connected with the vacuummotor 84 by means-o f'a conduitIH, and

I14 acted on by the solenoid I26.

duits I54 and I12.

9 the valve is connected with the vacuum conduit I69 by means of a conduit I13. The valve 83 is a two-position valve and comprises a valve piston When the solenoid I26 is deenergized, the valve piston I14 is in its position as shown in Fig. 2. In this position the valve piston blocks the conduit I13, and the valve connects the conduits I54 and I12. When the solenoid I26 is energized, the valve piston I14 is raised so as to block the conduit I54 and to connect the conduits I13 and I12. The vacuum motor 84 comprises a diaphragm I15 which is connected by means of a link I16 with a lever I11 that is fixed to the rock shaft 28 for the clutch actuating lever 21.

The valve 80 functions to cause engagement of the clutch I3 in accordance with the wishes of the driver of the vehicle as expressed through the accelerator 14, that is, the rate of engagement of the clutch I3 is under the control of the accelerator 14. The vacuum motor 84 in its condition as shown in Fig. 2 has no vacuum applied to it, and the clutch I3 is engaged. If vacuum is applied to the motor 84 through the conduit I12, the diaphragm I15 of the motor operates by means of the link I16, the levers I11, 21 and and the collar 25 to disengage the clutch I3 against the action of the clutch springs 24. If the solenoid I26 of the valve 83 is energized, the valve piston I14 is raised and vacuum is applied to the motor 84 through the conduits I13 and I12 for disengaging the clutch. If the solenoid I26 of thevalve 83 is deenergized to block the conduit I13, the vacuum for disengaging the clutch I3 must come through the conduits I52 and I54. When the solenoid I25 of the valve BI is energized, the valve 8| functions to connect the conduit I52 to the conduit I69 by means of the conduit I19, and the valve 80 may function to connect the motor 84 with the conduit I52, when the accelerator is depressed as will be described, through the conduits I54 and I12.

The valve 80 functions to engage the clutch I3 according to the depression of the accelerator 14 when the valve 8| connects the conduits I10 and I52 and when the valve 83 connects the con- When the accelerator is depressed, the lever I is rotated counterclockwise, as has been described, and this movement is transmitted through the link I63 to the plunger I59. The plunger I59 moves to the left as seen in Fig. 2 and moves the valve piston I55 also in this direction. Movement of the piston I55 in this direction functions to connect the conduit I 54 through the chamber I53, the passages I56 and the internal opening of the piston with the atmosphere to relieve the vacuum on the motor 84 to engage the clutch. The motor I acting through the floating lever I68 acts to .move the piston I55 back to the right as the vacuum is relieved on the two vacuum motors which are connected through the chamber I53 in causing an engagement of the clutch I3, and a small movement of the plunger I59 to the left as seen in the figure thus causes only a small engagement of the clutch I3 due to the action of the motor I65, all as will be more fully described below. The clutch I3 is fully engaged when the plunger I59 is moved sufficiently so that its stop I60 contacts the valve block I5I, and continued movement of the accelerator 14 thereafter toward its fully open throttle position causes movement of the levers I40 and I42 about the connectionof the lever I40 with the link I63 and the lever I40 about the pivot I48 to further open the butterfly valve 16.

The vacuum motor is controlled by means of the valves 81 and 88. The valve 81 comprises a valve piston I85 actuated by the solenoil I21. The valve is connected with a source of vacuum by means of a conduit I86 and with the motor 85 by means of a conduit I81. In the deenergized condition of the solenoid I21, the valve piston I85 is in its position as shown and blocks the conduit I 86. When the solenoid I21 is energized, the valve piston I85 is raised and functions to connect the conduits I86 and I81 for applying vacuum to the motor 85. The valve 88 is similar in construction to the valve 81, and the similarly numbered parts function in the same manner as those in the valve 81; the valve 88 is, however, connected to the opposite side of the motor 85 and functions to energize the motor in the opposite direction.

The motor 85 comprises a piston I88 which is acted upon by a pair of springs I89 and I90. The springs function to yieldingly maintain the piston in its neutral position as will be understood. The piston is also acted on by the holding coils I29 and I30 when the piston is in either of its extreme positions, and these coils function to augment the force of the vacuum acting on the piston and applied through one of the valves 81 and 88. The piston is connected to a shift lever I9 I, comprising a part of the lever and switch assembly 86, by means of a rod I92. The lever I9I is swingably disposed on a shaft I 93 which is rotatably disposed in the transmission housing 35 in any suitable manner (not shown). A shift element I94 is fixed to the shaft I 93,,and the shaft I93 has fixed thereto on its inner end an element I95 carrying the fork 69 which is disposed in the groove provided in the collar 55. The arrangement is such that when the shift element I94 is moved, the element I95 and the yoke 60 and collar 55 are given a corresponding movement.

The shift lever I9I and the shift element I94 have a lost-motion connection between them. This connection is provided by two lugs I96 and I91 disposed on opposite edges of the shift lever I9I. When the shift lever I9I is moved by the motor 85, the shift lever does not function to move the shift element until one of the lugs I96 and I91 contacts the shift element. The motor 85 is adapted to shift the shift element I94 and the collar 55 only a portion of the distance required for the meshing of the internal teeth of the collar 55 with the teeth 51 and 58, and the element I95 and the collar 55 are moved the remainder of the distance required for full engagement by ball and detent means. The ball and detent means comprises a ball I98 and a spring I 99 dis-posed between a stationary part 200 of the transmission housing 35 and the ball. Grooves 26I are provided in the shift element I95, and the ball I98 coacting with the grooves functions to move the shift element I95 and collar 55 into fully engaged positions after the motor 85 has functioned to move the shift element I95 into position so that the ball and detent means may become effective.

The switch I3I comprises a plunger 202 carrying the switch arm I33. The plunger extends through the lug I91 and is reciprocable with respect to the lug I91 and the plunger is acted on by the shift element I94. The switch is so arranged that when the shift lever I9I is acted on by the motor 85 so as to take up the lost motion between the shift element I 94 and the shift lever I9I, the switch arm I33 is moved to' contact 1 1 either. of the switch contacts I32 so as to, close the switch I31;

Operation:

Vehicle at rest, with ignition switch openp-In this, condition of the vehicle, the parts. of the transmission and its operating mechanism are as shownin Figs. 1 and 2; The transmission is in. neutral condition, and thegear 45 is in its out-of-mesh position, in which it is shown in Fig. 1. The. ignition switch 65 is open and none of the electrical parts of the controlling mechanism are energized. Theengine I2 is inoperative; and there is no vacuum in the conduit I69. The conduit' I693 is furthermore closed with respect'to the rest of the vacuum systemby the valves 81 and 83; the solenoids I25 and I26; being deenergized. N vacuum is therefore exerted'on themotor 84'; and the clutch I3 is engaged due to theaction of the clutch springs 25. The two springs I89 and I98. hold the piston I88 of. the vacuum motor 85 in neutral position, and the shift collar. 55 is in its neutralposition.

Transmission conditioned for low speed' forward, accelerator in closed throttle position; This condition of the operating mechanism for the transmission is shown in Fig. 3. In thisfigure, asv in the following figures, various of the parts of the transmission operating mechanism are shown in positions differing from. theirpositions shown inFig. 2, as is apparent. In Fig; 3 and in the following figures thev flow of current through the various electric leads is indicated by showing these leads in heavy lines and the exhausting of the. various conduits as Well as the subsequent admission of air therein isindicat-ed by appropriate arrows shown in the conduits indioating the direction of the, flow of air therein.

In. order to condition. the transmission itself for forward movement, the gear 45 is shiftedto the left as seen in Fig. l to bring it into mesh with the gear 48. The ignition switch 65 is, closed, and the forward direction switch (i1 is also closed. The engine I2" is started and is running in idling condition, and a vacuum is thus present in the conduit. I59. Due to the closing of the ignition switch 65, the solenoid I25 of; the valve 81 is energized to move the piston IiI of the valve upwardly to close the conduit I52 to the atmosphere and connect. it with the conduit I'IB. A vacuum isthereby caused to exist in the conduits I and I52, in the valve 8L, its chamber I53, the conduit [55, the valve 83 and inthe conduit IIZ so that vacuum is exerted on the diaphragm I ofjthe vacuum motor 84. The diaphragm. H5 is thereby moved and is elfective through the link I16, the levers Ill and Z'l and the clutch levers 20,: to pull the pressure plate I9 of the-clutch I3 rearwardly to disengage the clutch. The valve '80 is conditioned for operation by movement of the diaphragmof the motor I55 against the spring I58 due to. the vacuurnxbeing exerted on the dia phragm through the conduit IG I. This movement of the. diaphragm of the motor I65 through the plunger I64 functions to move the valve piston I55 to the left as seen in the figure to substantially align its land I58 with the openings I56.in. the valve 89:. The two diaphragms I'i5 and that. of the motor I55 and the springs acting on these diaphragms are so adjusted with respect to each other that the valve'piston I55functions to substantially block the, openings I56 when the clutch I3 is infully disengaged condition.

Accelerator depressed for starting the ce-hicle. This condition of the operating mechanism of thetransmission is. shown inliig. 4:. The vehicle is started by. depressing. the; accelerator I14: The depression of the accelerator functions. through the linkage mechanism I! toopen. the butterfly valve 1540f the throttlev 1-5%for increasing thespeed of: theiengine I2: Such movementof; thelevers I49. and I423 of: the linkage T'Iihas the: additional functioniof causingmovementofthe plunger I59 to thelleft as seen in the figure. through the link I63; and: fertile present-it is assumed that the accelerator has been. depressed only: enough to give the: plunger a small movement: This move-- ment: of theplungen causes: a smallzmovement: of the valve-piston I in-7the same direction. This movement of the valve piston operatesato connect the; motor 84' through theccondui't I112; he: Valve 83;.the conduit I 5.4 thechambe'r I53;}-the.passages I 56,,and throughtheinternal openingiin the; valve iston. I55; with the atmosphere for allowing-a movement. of; the; diaphragm. H 5: of: the, motor: 8.4 toward; the. right; as secrrin-v the. figure with. a;- re;-

sultant engaging movement ofjthe clutclrpres sure plate. I 9..- This;decrease invacuum in these conduitsI and in, the chamber I 53- causes a. correspondingdecrease in vacuumappliedzta the diaphragm of, themotor I" through; the conduit IBI connected with the chamber I53: The diaphragmof the motor I65; thus; hasasmall movement tolthe right as seen; inthe figure which is causedby the spring I66 to thereby cause a-small movement of; the valve piston. I55 in this direction. This movement of.- the valvepiston. I55 again: brings theland'; I5- of" the piston over; the passages I56; to prevent a; further; decrease, in the vacuum; inrthe-conduits- I54, I12, and I61, and the clutch I3-remains in partially engaged condition. It will-beunderstoodthat the clutch controlling valve I55 is controlledjointly bythe plunger. I59 and theplunger I64 through the agency of the floating, lever I68, andythis: movement of the plunger 4 I59 in one direction and. of the plunger I64 in: the other'direction results-in the, return of the-valve- I55to. its initial position blocking the passages I56.

Further, small movement of the plunger I59 to the leftasseen in the-figureby means of'the accelerator 14v thus causes acorresponding small movementof the pressure plate- I9.-of the-clutch I3- toward fully engaged position, and it will be apparent that the clutch. I3 can beengaged; as quickly-as possible or in-as many small difierent steps as desired. simply by accordingly moving theaccelerator'l l toward open throttle position. This-movement of the accelerator, it, willbe understood, causes corresponding movements; of the butterfly valve I5, and it will be apparent that an increasing amount. of fuel is fed to the engine I2 by'means of the accelerator at the samestime as the clutch I3 is brought toward fully engaged condition.

The-lost motion between the-link I40 and the portion. I50. of the lever- I42 is-provided. so: that the. clutch I3-is slightly. engaged beforethe butterfly valve 76 is moved from its engineidl-inglposition- This. prevents the, engine from being brought to a destructive or harmful-speed before there is, any. engagement of the clutch. This slight. engagementv of the clutchlis due to the fact thattheplunger I59 is givena small movement beforethevalve IE ismoved by means of. its linkage. The groove I52 isprovided: in the plunger for providinga direct connection with atmosphere from the chamber I53'when the. plunger is. moved to the limit of its movement with. the stop. I80 contacting the valve block I5'I. A release of vac- 13 uum on the vacuum motor 84 is thereby made quicker, as when the accelerator is moved quickly to fully opened position, inasmuch as the air in this case entering the chamber I53 and associated conduits need not all flow through the small passages I56.

When the plunger I59 is moved to the limit of its movement with its stop I59 contacting the valve block II, the clutch I3 is fully engaged. The stop I69 makes such contact when the accelerator is approximately in its half open throttle position. Thereafter the lever I40 piovts about its connection with the link I63'and the lever I42 pivots about its pivot point I43, and the linkage 1! on further depression of the accelerator functions to further open the butterfly valve I6 to further increase the speed of the engine I2.

As is apparent from an inspection of the construction the greater the decrease in vacuum in the conduits I54 and I72, the greater is the engagement of the clutch I3. In starting the vehicle, particularly in cold Weather, it frequently happens that the motor begins to stall. Under such conditions, the vacuum in the manifold of the engine decreases, and there would be resulting decrease in the vacuum in the conduit I69 and thereby in the conduits connected therewith. Such stalling of the engine would thus cause a further engagement of the clutch I3 and would increase the load on the engine whereby the engine would be certain to completely stall. The one-way valve 82 is provided for preventing this increase in engagement of the clutch I3 when the engine starts to stall. When there is such a decrease in vacuum in the conduit I59 due to stalling of the engine, the valve 82 closes and maintains the-vacuum in the conduit Ill] and the conduits connected therewith at the same high value as before the stalling to maintain the clutch I3 in the same condition of disengagement as previously. When the engine again begins to operate normally, the valve 82 reopens in response to the increase of vacuum in the conduit I69, a.nd the operation of the clutch I3 under the control of the valve 89 proceeds as has been described.

When the clutch I3 has been thus engaged, the driven shaft II is driven in low speed ratio, the gear train of which has previously been described. Since the gear train includes the one-way clutch 41, this low speed drive is a free wheeling drivel Vehicle traveling above five miles per hour, accelerator released to open throttle positionto upshift transmission to second speed.This condition is shown in Fig. 5 of the drawings. An upshift from first speed to second speed ratio is obtained by releasing the accelerator I4 and allowing it to return to its closed throttle position under the action of the springs I 2! and I49, after the speed of the vehicle has reached five miles per hour. At five miles per hour speed of the vehicle, the governor contacts IIO close and the governor contacts I99 open, as has been 'described. Such opening of the contacts I09 breaks the electric circuit through the solenoid I25 for the valve BI, and the valve piston I'II returns to its position blocking the conduit I and opening the conduit I52 to atmosphere. After such movement of the valve-piston III, the clutch I3 cannot thereafter be disengaged due to the action of the accelerator I4.

When the accelerator returns to its closed throttle position, the contacts II4 are closed by the switch arm II9 carried by the accelerator plunger III. An electric circuit is thus completed from the battery 66 through the switches 65 and 67, the winding I99 ofthe relay 69, the

r nected with the atmosphere.

contacts II4 of the accelerator switch I3 and the contacts III! of the governor "I2 to ground. The relay 69 is thus energized and its contacts IIlI are closed and complete a circuit from the lower end of the winding I09 to the governor contacts I I 9 and from thence to ground, this circuit being in parallel with that through the contacts I I4 of the accelerator switch 13. Thus after the contacts H4 are once closed by movement of the accelerator I4, the relay 69 remains energized regardless of the subsequent depression of the accelerator. The contacts I02 of the rela 69 are closed when the relay is energized and they complete a circuit from the battery through the switches 65 and 61, the contacts I92, the contacts 91 of the relay 68, the solenoid I2! and the holding coil I29 to ground. The solenoid I21 is thus energized to control the valve 81.

Upon the solenoid I2! being thus energized, its valve piston I is moved upwardly to effectively connect the associated conduits I86 and I8! and apply vacuum to the left side of the piston I88. The valve 88 remains in its original condition and the other side of the piston is effectively con- Such application of vacuum on the piston I98 causes the piston to move toward the left as seen in the figure to thereby pull the shift lever I9! in a clockwise direction. The lug I97 of the shift lever makes contact with the shift element I94 and exerts a pressure on the shift element tending to move the shift element I94 and the collar 55 to engage the collar with the teeth 58 of the gear 43.

The switch I 3| functions when such a force is exerted on the shift lever I9I to cause a disengagement of the clutch I3 and-an incidental closing of the throttle I5 by means of the butterfly valve I8. As has been described, the switch I3I is closed when the shift lever I9! is so acted on by the motor 85 to tend to cause a shift of the collar 55. The switch I3I completes a circuit through the solenoid I25 for the valve 83 from the ignition switch 65, and the switch I 3| also completes a circuit from the ignition switch through the solenoid I9 for the butterfly valve I8. The energization of the solenoid I26 causes the valve piston I14 of the valve 33 to move upwardly and connect the conduits I13 and H2. Vacuum is thus exerted on the diaphragm "5 of the motor 84 through the conduits I13 and IT! to disengage the clutch I3. Energization of the solenoid I9 acts on the armature I24 of the solenoid I9 and rotates the butterfly valve I8 to engine idling position, and the valve I8 remains in this condition as long as the switch I3I is closed. While the motor 84 by means of the switch I3I thus functions to disengage the clutch I3 and bring the speed of the engine I2 to idling condition, the motor 85 functions to move the collar 55 into engaged condition with the teeth 58 of the gear 43, with a synchronizer 59 functioning to synchronize the speed of the collar 55 and the gear 43 before a full engagement of the collar with the teeth. The disengagement of the clutch I3 allows an easy engagement of the collar with the teeth and an easy functioning of the synchronizer, and the action of the butterfly valve 73 is such that the engine I2 cannot be increasedto harmful speed while the clutch is disengaged regardless of the fact that the accelerator H may be depressed after the shift has once been initiated.

Vehicle speed above five miles per hour, upshift to second speed ratio completed, accelerator still releasecl.This condition of the controlmechanism, is shown in Fig. 6. As has been described, the motor 85 is efiective for shifting the collar 55v through the greater part of its shiftin movement, and the ball and poppet means comprising the spring. I99 and the ball I98. is efiective to complete the shift. When the ball and poppet means functions in this manner, the shift lever I9'I and the shift element I94 move back to their original relative positions in which the lugs I96 and I 91 are out of. contact with the shift element I94. When the shift lever and the element: have such relative movement, the switch I 3I opens, inasmuch as the condition of the switch I3I is dependent upon the relative positions of the shift leverandthe shift element. Such opening of the switch. I3I opens the circuit through the solenoid I9 for the butterfly valve I8 in the throttle I5 and also the circuit for the solenoid I26 for the valve 83. The butterfly valve I8. returns to its. throttle opening position and the am'ountof fuel thereafter flowing through the throttle I5 to the engine is dependent only on the position of the butterfly valve lii'elosed mechanically from the accelerator I4. When the solenoid I26 of the Valve 83 is dee-nergized, the valve piston I14 returns to its position blocking the conduit I13 and connecting the conduit I54" with the conduit I12; Vacuum is thus released on the diaphragm II5'of: the vacuum motor 94 and air flows through the valve III, the conduit I52, the valve 80, the conduit I54, the valve 83 and the conduit I12, as is indicated by the arrow-s in the figure. The diaphragm thus moves to the right as seen in the figure and the clutch I3 is again engaged under the action of the clutch springs 2'4.

With the clutch I3 being engaged and the collar 55 being moved into engagement with the teeth 53; the transmission is in second speed ratio. The gear 45 remains engaged with the gear 48 in this speed ratio; however, there is no drive through these two gears inasmuch as the one-way clutch i! overruns. The piston I88 is held in its illustrated position by the holding coil I29, when the transmission is in this speed ratio, and the holding coil functions in addition to the vacuum applied on the piston I 88through the valve 81 to hold the piston in its illustrated position. Therefore, even if the vacuum momentarily decreases, the piston nevertheless remains in its illustrated position corresponding to second speed ratio.

Vehicle speed above five miles per hour, accelerator depressed, after shift to second speed ratio.This condition of the control mechanism is. shown in Fig. 7. The clutch I3 remains engaged and the motor 84 for the clutch remains in communication with the atmosphere. The accelerator I4 in being depressed moves the plunger I59 of the valve 80'to the left as seen in the figure to disconnect the conduit I52 with the chamber I53 of the valve; however,- the conduit I54 and the chamber I53 remain in communication with the atmosphere through the internal opening of the valve piston I55 of the valve 80. The depression of the accelerator also changes the condition; ofthe accelerator switch I3. The contacts I-I4 are open, and the current therefore ceases to flow through the contacts; the relay 69 is, however, continued in energized condition by means of the circuit through the contacts IOI' of the relay and the contacts I I of the governor I2.

The contacts II5 of the accelerator switch I3 are closed by the depression of the accelerator and as a result the relay I0 is energized. The switch arm II9 on a depression of the accelerator plunger II'I, completes.- a. circuitv across. the contacts, I I 5-, and a, circuit: is therebycompleted from the ignition switch, 65,- through, the. switch 6'I-, the contacts I02, of the relay 69, the winding I03 of the'relay I0- and the contacts I I5 of the accelerator switch I3 to ground. The relay I0 is thus energized to close the contacts I04 and I05 of the relay. Closure of, the contacts I04 completes a circuit to ground through the winding I03 of the relay which is in parallel with. the circuit from the winding through the contacts N5 of the accelerator switch I3. The relay- I0thereafter thus remains energized: regardless of whether or not the accelerator is so moved as to break the circuit between, the contacts H5. Closure of the contacts I05 of the relay I0 conditions a circuit through the-winding 96- of the relay 68 for energizationby the accelerator switch I3- as will be described. During energization of the relay I0 by movement of the accelerator, the transmission remains in second speed ratio, and the shaft. II is driven: through the clutch and gears as has been described.

Vehicle speed above ten miles per hour, accelerator moved; to closed throttle position to shift from. second to thind speed ratios.-This condition of the transmission control mechanism, is shown, in Fig. 8. Above ten miles per hour speed of the vehicle, the contacts III of, the governor I2 are closed. These contacts are in series with the contacts N6 of the accelerator switch, and these two sets of contacts complete a circuit from the ignition. switch 65, through the switch 6-1; the winding 96 of the relay 68-, the contacts I05 of the relay III, the contacts I06 ofrthe switchII, the contacts H3 or the accelerator switch 13,1and the contacts III; of the governor 12. The relay 68 is thus energized. and the contacts 98 and 99 of: this relay are, closed while the contacts 91' of this relayare opened. Closure of the contacts 98 complete an additional circuit from the bottom of thewinding 96- of the relay 68 to the contacts I I6 of the accelerator switch I3- which is in parallel with the circuit from the winding 96 through the contacts I05, the contacts I06 and the contacts II3 to the contacts IIB. By means of this additional circuit, the relay 68' is continued in energized, condition regardless of whether or not the accelerator is; depressed to open the contacts I I3 afterthe relay 68 has oncebeenenergized.

Opening of the contacts 91 of the relay 68 has the: effect. of: breaking: the electric circuit; through the; solenoid. I217 for the-valve 81 and deenergizing th'e holding-coil I29. The valve; piston I85 ofthe valve 81 thus returns to its: original position blocking the, associated conduit I86-and connecting the associated conduit I81 with the atmosphere. The spring I maythen be efiective to move the piston I88 to its neutral position. Closure of the contacts 99 of the. relay 68 has the eifect' of completing a circuit from the ignition switch 65 through the switch 61 andthe contacts 99 to the solenoid I28 and through the holding coil I30. This energization of the solenoid I28 causes the valve piston I85 of the valve 88- to move to its upper position and connect the associated conduits I86 and I8"! while disconnecting the conduit IBI from the atmosphere. Vacuum is thus applied to the right hand end'of the piston I88 and functions to move it toward the right as seen in the figure.

The force exerted on the piston I88 by the spring I90 andby the vacuum tending to move the piston toward the right as seen in the figure causes the lug I96. of the shift lever I9I to contact.the; shift: element I94; and this change in 17' relative position between the shift lever I9I and shift element I94 causes the switch I3I to be closed. The switch I3I when closed functions in the same manner as has been described in connection with the upshift from first to second speed ratio, which is illustrated in Fig. 5, to energize the solenoid I28 of the valve 83 and energize the solenoid 19 connected with the butterfly valve 18. This energization of the solenoid I26 causes the valve piston I14 to move upwardly and connect the conduits I13 and I12 for thereby applying vacuum to the motor 84, and the motor is then effective to disengage the clutch I3. The energization of the solenoid 19 functions to move the valve 18 to an engine idling position, so that the engine I2 remains in this condition regardless of whether the accelerator is depressed or not after the shift has once been initiated. With the clutch I3 being disengaged and the engine being maintainedin idling condition, the spring I90 and the vacuum exerted on the opposite side of the piston I88 causes the shift lever to shift the shift element in a counterclockwise direction to disengage the collar 55 from the teeth 58 and to engage the collar with the teeth 51. The synchronizer 59 between the collar 55 and teeth 51 is effective to synchronize the speed of the collar and the teeth prior to engagement thereof, and such engagement is easily performed since the clutch I3 is disengaged, The transmission is now vconditioned for third speed drive. The piston I 88 is held at the limit of its movement to the right by the holding coil I38 as well as by the vacuum applied thereto through the valve 88. The

switch I3Iopens when the coll'ar55 is fully engaged with the teeth 51 due to the action of the ball and detent means comprising the spring I99 and ball I98 and the solenoids I28 and 19 are thereby deenergizedf The deenergization of the solenoid I28 actuates the valve 83 to reengage the clutch, and the deenergization of the solenoid 19 causes an opening of the butterfly valve I8 so thatthe opening through-the throttle is thereafter solely under the control of the accelerator- 14. The solenoids I26 and 19 function to engage the clutch I3 and openthe butterfly valve 18in the same manner as in a shift from first to second speed ratio as is illustrated in Fig. 6. The gear 45 remains engaged with the gear 48 in high speed ratio; however, the one-way clutch 41 overruns, and there is no drive through these gears. V Vehicle speed above ten M. P. H., accelerator depressed to open throttle position to downshift the transmission from third to second speed ratios-This condition of the operating mechanism of the transmission is shown in Fig. 9. The accelerator 14 in its depressed open throttle position functions with the remainder of the operating mechanism to downshift the transmission from third'speed ratio to second speed ratio,

as when it is desired by the operator to obtain a high torque for passing another vehicle on the ,road, for example. It is to be noted from Fig. 8

that the relay 68 is kept in energized condition .by means of a circuit through the contacts H6 .Deenergization of the relay 68 hasthe effect of opening the contacts 98 and 99 of therelayand 10f, closing the contacts 91 of the relay.

Opening of the contacts 99 of the relay 68 has the effect of deenergizing'the holding 0011 I38 and deenergizing the solenoid I28 of the valve 88 and returning the valve piston I of the valve 88 to its position in which it closes the vacuum conduit I86 connected with the valve and opens the associated conduit I81 to the atmosphere. Closing of the contacts 91 of the relay 88 has the effect of completing a circuit from the ignition switch 85 through the switch 61, the contacts I02, the contacts 91, to the solenoid I21 and the holding coil I29. The valve piston I85 of the valve 8'5 is moved by energization of the solenoid I21 to disconnect the associated conduit I81 with the atmosphere and to connect the associated conduits I88 and I8? together. Due to these changes in condition of the valves 81 and 88, the spring I89 is effective to move the piston I88 toward the left, and the vacuum exerted on the piston through the conduit I81 connected with the valve 81 is also effective to move the piston in this direction. It will be noted that the other relays 69 and I8 remain intheir energized conditions, as they were prior to'the kickdown by the accelerator.

The piston I88 exerts a force on the shift lever I9I tending to move it in a clockwise direction, and the lug I91 of the shift lever contacts the shift element I94. On such change in relative positions of the shift lever and shift element, the switch I3! is closed, as has been described,and the switch completes electric circuits through the solenoid 19 for the butterfly valve 18 and through the solenoid I28 for the valve 83. Such energization of the solenoid I9 closes the butterfly valve 18 to engine idling position, and such energization of the solenoid I28 raises the piston I14 to disconnect the conduit I12 with the conduit I54 and to connect it instead with the conduit I13. The valve 83 is thus effective to apply vacuum to the motor 84 for disengaging the clutch I3. As is apparent, the switch I3I when closed is effective in the same manner as in an upshift from low speed ratio to second speed ratio which has been heretofore described and is illustrated in Fig. 5. The clutch I3 is disengaged and the engine I2 has been reduced to idling speed, regardless of the fact that the accelerator I4 is in open throttle position, as has been described, and the piston I 88 is then effective to shift the shift lever I9I and collar 55 to engage the collar with the teeth 58. The synchronizer 59 between the teeth and collar acts as before to synchronize the speed of the collar 55 and teeth 58 before engagement thereof. When the piston I88 has completed its stroke, the spring and poppet means including the ball I98 and spring I99 is efiective to complete the shift of the collar, and in such a completion of the shift, the switch I3I is opened. Such opening of the switch deenergizes the solenoid I26 for the valve 83 and also the solenoid I19 for the butterfly valve I8, and the drive is then through the transmission in second speed ratio with the clutch I3 being engaged and the throttle 15 being completely under the control of the accelerator 14. I

The forty mile per hour contacts II2 of the governor 12 are effective for preventing a. kickdown from third speed ratio to second speed ratio by means of the accelerator when the vehicle is travelling above this speed. The contacts I I2 connected with ground, it will be noted, are in parallel with the circuit including the contacts IIIS of the accelerator switch 13 and the governor contacts III. Therefore, it will be apparent that an opening of the contacts IIB by a depression of the accelerator 14 when the contacts H21 are closed can'have noeffect 'in do energizing relay 63 for shifting from third speed ratio to second speed ratio. The governor contacts IIZ thus advantageously operate to prevent a downshift above the speed at which a downshift would not produce any substantial increase in torque and would allow the engine to attain destructive or harmful speeds.

The coast switch II is effective when moved from its position as shown in the drawings connecting the contacts I06 to its lower position connecting the contacts ii]? to prevent an upshift from second speed ratio to third speed ratio or to downshift the transmission to second speed ratio if it is in high speed ratio. This switch is useful when the vehicle is descending a steep grade at which time it is desired to use the engine I2 as a brake for the vehicle. As has been described in connection with Fig. 8, the circuit for energizing the winding 96 of the relay 68 for shifting the transmission from sec ond speed ratio to third speed ratio includes the contacts Hi5, the contacts I96 of the coast switch II, the contacts I E3 of the accelerator switch it, the contacts I It of this switch and the governor switch III. By moving the switch 5'! from its illustrated position to its position connecting the contacts I01, this circuit is broken, and a release of the accelerator i4 cannot function to shift the transmission into high speed ratio. The switch H in connecting the contacts functions to energize the relay $9 and to maintain it energized. As has been described in connection with Fig. 5, the energization of the relay 69, when the relay 68 is deenergized, causes a shift of the transmission to second speed ratio,

a circuit being completed from the ignition switch through the forward direction switch 6'5, the contacts Hi2 of the relay 6%, the contacts 9? of the relay 68, the solenoid E2? of the valve and the holding coil I29. As has been described in connection with the latter figure, the upshiit from first speed to second speed is ordinarily made by a circuit from the ignition switch including the forward direction switch er, the winding I60 of the relay 69, the contacts lid of the accelerator switch I3 and the contacts i icof 'the governor switch I2; however, the coast switch ii in connecting the contacts is? accomplishes this function of energizing the relay so simply by grounding the winding we of the relay, and it is not necessary to connect the contacts i ii of the accelerator switch it by bringing the accelerator to a closed throttle position.

In order to shift the transmission into reverse the gear is simply shifted from its neutral position in which it is shown in Fig. l rearwardly to interengage its teeth'53 with the teeth 52 of the element 5i splined on the driven shaft i i. In so moving the gear 45, it is also brought into mesh with the idler gearfill. The forward direc tion switch $1 is also opened, and this has the effect of maintaining deenergized all of the relays 68, 69 and it and the associated electrical circuits. When the vehicle is running in reverse drive, therefore, the shift lever I9! is not shifted by the motor 85, inasmuch as neither of the solenoids i2? and :23 is at any time energized. The solenoid I25 is energized through the governor contacts I09 when the vehicle speed i less than five miles per hour in reverse drive whereby the valve BI connects the conduits lit and 552. The clutch I3 is thus engaged and disengaged under the control of the accelerator I'd in reverse drive in the same manner as in forward drive.

20? 'Modificd transmission controlsystcm A modified transmission control system as shown in Fig. 10 in the condition in which it is with the accelerator depressed toopen-throttle position. It has been found in certain embodiments of the transmission control system in its form in which it is shown in Figs. 2 to 9 that if the conduits I86 and I8? are too small in diameter, the springs E89 and IE5! act so quickly that the vacuum on the piston I88 did not become eifective in time to maintain the switch i3I closed for the entiremovement of the piston from its second speed ratio position to its third speed ratio position or vice versa. This resulted in an engagement of the clutch 13 before the shift was completed. This modification, as shown in Fig. 10, has been designed to obviate this difficultywithout changing the conduits I33 and i8! or the springs E83 and I99 in any way.

The change of the Fig. 10 embodiment over that shown in Figs. 2 to 9 comprises the addition of a switch 2!!) actuated by the vacuum motor 85. The switch 2 I I3 comprises a pivotally mounted switch arm 2! I having a pin and slot connection 2I2 with the link I92. The switch arm 2II is an electric conductor and cooperates with a contact 2I3 in the form of an arc. The are 2I3 is continued on its ends by portions 2I4 which are of nonconducting material. The switch arm ZII is connected with one of the contacts I I4 of the accelerator switch I3, and the contact 2I3 of the switch is connected with the contacts I32 of the switch IEI. As is apparent, the switch 2H] is closed when the piston I88 is in neutral position and is open when the piston I88 is in either of its positions providing the second or third speed ratios through the transmission.

After the transmission has been shifted from second to third speed ratio and the accelerator is depressed to downshift the transmission, the control mechanism is in condition in which it is shown in Fig. 10, assuming that the spring I89 has acted before the vacuum has had effect on the piston I88 to move the shift lever I9I to neutral position. In this condition of the mechanism, the ball and detent means comprising the ball H98 and the spring I99 is effective to move the shift element I94 to its neutral position, so that the switch I3I is open. In this case, the solenoid I26 for the valve 83 and the solenoid 19 for the butterfly. valve I8 are maintained energized, so that the engine is held in engine idling condition and the valve 83 continues to cause the clutch to remain disengaged, by a circuit in lieu of the switch I3I which comprises the switch ZIII, the contacts IIlI of the relay 69 and the contacts [I0 of the governor I2. The throttle solenoid I9 and the valve solenoid I26 thus remain energized, although there has been a temporary stop in the movement in the piston I88 resulting in an opening of the switch I3I. If the same condition should exist, that is if the switch I3I should be temporarily opened, when the transmission is being upshifted from second speed ratio to third speed ratio, the switch ZIO functions in the same manner to complete circuits through the solenoids I9 and I26 for maintaining the clutch I3 disengaged and the throttle valve I8 closed during the shift. 7

My improved transmission control mechanism advantageously provides a forced upshifting from first to second and from second to third speed ratios without the-possibility that second speed may be omitted. The vacuum motor for shifting the transmission in conjunction with the switch 

